Solar heat reflecting plate glass is increasingly used in contemporary architecture to control the heat gain of internal environments through the glass. To decrease further heat transmission and to increase the aesthetic reflective quality of the glass, a thin metallic oxide film is often deposited on one surface of the glass. Conventional coating methods, however, have numerous shortcomings. When the film is applied to one side of a single layer of glass, the film may be damaged by the abrasion caused by dust when the glass is cleaned or wiped and by the action of the weather. Consequently the film is often deposited on the surface of a layer of glass, which surface is then bonded to a second layer of glass. This protects the film from abrasion and weather. In addition, conventional bonding agents further curtail the tendency of the glass to shatter dangerously when broken. However, the relatively high water content (0.3 to 0.8% by weight) of conventional bonding agents used to curtail shattering tendencies causes chemical reactions which often discolor the film and cause small pin holes to develop in the film.
The objects of the present invention are to eliminate the above mentioned defects, to provide a multi-layered safety solar heat reflecting glass with a metallic oxide film in which the film is protected from abrasion, the action of weather, and discoloring and becoming blurred, and which will not shatter when broken.